Avg. lifespan of a species on earth = Not long

Did you know that most animals that live today (including humans) are new to the world? We are new as a species. Only a few ones have remained unchanged for millions of years.

This made me think... what can we look at here to determine our chances? Well how about if we look at the average age of a species. I found out that the average age of a species is only a few million years. How lucky do you feel? Considering that only a few species have made it longer, (one has lived 500 mill years) id say that time is running out for most of the species on earth right now.

*Mammals, for instance, have an average species "lifespan" from origination to extinction of about 1 million years, although some species persist for as long as 10 million years.

*Consider this: There are about 5,000 known mammalian species alive at present. The past 400 years have seen 89 mammalian extinctions.




The sad thing is, humans have become quite responsible for these extinctions. If present trends continue, a mass extinction is very likely underway. This time, unlike the past, it's not a chance asteroid collision, nor a chain of climatic circumstances alone that's at fault. Instead, it is chiefly the activities of an ever-growing human population, in concert with long-term environmental change.


*The background level of extinction known from the fossil record is about one species per million species per year, or between 10 and 100 species per year (counting all organisms such as insects, bacteria, and fungi, not just the large vertebrates we are most familiar with).

*In contrast, estimates based on the rate at which the area of tropical forests is being reduced, and their large numbers of specialized species, are that we may now be losing 27,000 species per year to extinction from those habitats alone.



What is the fate of our own species likely to be, if we really are in the midst of a sixth mass extinction? Homo sapiens, the most dominant species in history -- could also be on the road to oblivion. But another possibility is that Homo sapiens, will persist.


mammoth:


phororhacus:


[edit on 17-9-2008 by Daniem]

Yes, but to date we are the only ones, known to have cultivated food, keep animals. store water, we have amazing technology, and have been extremly successful in life as a species.

alough we may be the first to destroy ourselves through overpopulation...

I beleive that we are in the midst of a strong, worldwide, selective event but I don't think that it is a mass extinction as has happened in the past.

Many species will survive the coming changes through adaptation.

One problem in these sort of estimations is that we only have rough estimates of the number of species on the planet, and the definition of a species has been an ambiguous issue since Darwin.

Short of a cataclysmic event, I don't think we will see a mass extinction.

Edit: As a side note, a species can be viewed as a constantly evolving population. This could also affect the perceived age of different species. I think what this really tells us is that the Earth is a dynamic place, always subject to change. The biological species concept does not factor in gene flow and adaptation over time.

[edit on 17-9-2008 by seenitall]